1. Field of the Invention
The invention concerns a joint assembly for wall members of casing cells, box-shaped apparatus housings, cable shafts or similar casings, the wall members being adapted to accommodate with adjacent ones and fixed preferably detachably to each other, defining at least one main wall surface and at least two abutting faces inclined at an angle to the main wall surface, and fitted with each other by means of joining elements of the groove and tongue type, each of the abutting faces abutting against a complementary abutting face of the respective adjacent wall member to define a joint gap therebetween, which joint gap is penetrated by the tongue-type one of the joining elements whereas a groove type element is provided with a protruding edge undercut in an opening direction of the respective wall members and the tongue-type element is fixedly arranged on the adjacent wall member to receive the groove type element in a snugly fitting manner. The invention also concerns the use of such joint assemblies for box-shaped casing cells to be used for an air-conditioning apparatus comprising a refillable and float controlled water reservior, an air-humidifying system associated to the reservior via hoses and arranged in several of the wall members of the casing cell especially in the form of a water absorbing cushion, a motor-driven ventilator for ejecting the moistened cool air, and an exit opening provided in one of the side wall members.
2. Description of Prior Art
Today it is still often usual, when assembling appliance casings, to fit the single wall members to each other by screwing or otherwise to join them by soldering, riveting or the like. On the one hand, such manufacture is expensive and many separate parts have to be provided, while, on the other, the opening of the housing in the case of e.g. repairs or adjustments has to be carried out by means of special tools and necessitates a relatively large amount of work apart from the fact that small fastening elements such as screws can easily be lost. Apart from these positive or non-positive joints of course, also purely positive arrangements are known where the single wall members engage each other in a sliding seat.
However, in the building of appliances in general, and especially in the relevant fields of use, e.g. in the manufacture of air-conditioning and heat appliances as well as the manufacture of measuring instruments one has now turned to clamp joints in the form of resilient catches which engage in some undercuts correspondingly arranged in a fixed part of the appliance. The arrangement of such resilient members producing a positive and non-positive joint is, as a rule, very costly. It mostly concerns some projecting parts which either, in the case of cast or ejection moulded elements, must be formed integral in a special mould or which, in the case of metal casings, must be formed out of the wall surface by punching or bending. Besides, such tongue-shaped joint elements break off easily. At least they lose shape quickly if used a lot so that the locking pressure is often considerably affected after a few opening and shutting procedures. A further disadvantage of such clamp-locking joints is that they are usually only arranged and work punctiform which therefore leads to a varying stress on the edges of the locking wall member and leads to leaks, which is rather disadvantageous as a certain sealing effect must be achieved.
Special difficulties have been found in the construction of joints of wall members in air-conditioning appliances which are used to cool the air particularly in countries with low air humidity. Such appliances are internationally known under the name "Air Cooler" and are usually built in the form of a parallelepiped or a cube. An upper and a lower wall member, i.e. a floor and a cover, are fixedly connected to one of the side wall elements in these air coolers. The floor carries the water reservoir with a water pump and a float valve while the cover merely has a locking function and carries the water distribution pipes, whereas there is a large exit opening for the cold air arranged in the fixed side wall member which carries a radial ventilator.
There are four corner beams which are screwed, welded or riveted to the three fixed elements. The technical effort for mounting and fixing such casings, which mostly comprise wall members of galvanized sheet steel, is very large since expensive special machines and specialists are needed as well as a great amount of time. Three detachable wall members are arranged on this basic building unit which incorporate wood-wool or excelsior cushions in correspondingly designed frames. The actual humidifying of the air occurs via these excelsior cushions in which the water is finely distributed. The moveable side wall parts can be inserted in the fixed building unit.